Editor mode is now stored as a global preference in VaultConfig instead of
being tracked per-tab. Toggling raw mode persists across tab switches and
app restarts via the editor_mode field in config/ui.config.md.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Sidebar section visibility is now controlled entirely by the `visible`
property on Type notes. Removes all hidden_sections references from
Rust struct, TypeScript interface, config migration, mock data, and tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>